The NTSB issued recommendations to the FAA aimed at preventing the kind of dual engine flameouts that have occurred on three Beechjet 400 aircraft in the last 2 years that the Board is investigating. The planes were equipped with Pratt & Whitney Canada JT15D-5 engines. One of the recommendations is classified as Urgent. The urgent recommendation said that the FAA should require Beechjet 400 pilots to activate ignition and anti-ice systems at high altitude whenever they are in or near visible moisture, or near convective storm activity, or before any power reduction while in those conditions. The Safety Board believes that many pilots may not be aware of the risk posed by ice crystals at high altitudes. The Board issued three other recommendations dealing with the kind of information provided to pilots and with research to develop an ice detector that would alert pilots to internal engine icing. (NTSB)